<template>
<div class="home-page">

    <div class="banner">
        <div class="container">
            <h1 class="logo-font">conduit</h1>
            <p>A place to share your knowledge.</p>
        </div>
    </div>

    <div class="container page">
        <div class="row">

            <div class="col-md-9">
                <div class="feed-toggle">
                    <ul class="nav nav-pills outline-active">
                        <li class="nav-item" v-if="user">
                            <nuxt-link class="nav-link" exact
                             :class="{
                                 active: tab === 'your_feed'
                             }"
                             :to="{
                                 name: 'home',
                                 query: {
                                     tab: 'your_feed'
                                 }
                             }">Your Feed</nuxt-link>
                        </li>
                        <li class="nav-item">
                            <nuxt-link class="nav-link" exact
                             :class="{
                                 active: tab === 'global_feed'
                             }"
                             :to="{
                                 name: 'home',
                                 query: {
                                     tab: 'global_feed'
                                 }
                             }">Global Feed</nuxt-link>
                        </li>
                        <li class="nav-item" v-if="tag">
                            <nuxt-link class="nav-link" exact
                             :class="{
                                 active: tab === 'tag'
                             }"
                             :to="{
                                 name: 'home',
                                 query: {
                                     tab: 'tag',
                                     tag: tag
                                 }
                             }">#{{tag}}</nuxt-link>
                        </li>
                    </ul>
                </div>

                <div class="article-preview" v-for="article in articles" :key="article.slug">
                    <div class="article-meta">
                        <nuxt-link :to="{
                            name: 'profile',
                            params: {
                                username: article.author.username
                            }
                        }"><img :src="article.author.image" /></nuxt-link>
                        <div class="info">
                            <nuxt-link class="author" :to="{
                            name: 'profile',
                            params: {
                                username: article.author.username
                            }
                        }">{{article.author.username}}</nuxt-link>
                            <span class="date">{{article.createdAt | date('MMM DD,YYYY')}}</span>
                        </div>
                        <button class="btn btn-outline-primary btn-sm pull-xs-right"
                         :class="{active: article.favorited}"
                         @click="onFavorite(article)" :disabled="article.favoritedDisabled">
                            <i class="ion-heart"></i> {{article.favoritesCount}}
                        </button>
                    </div>
                    <nuxt-link :to="{
                        name: 'article',
                        params: {
                            slug: article.slug
                        }
                       }" class="preview-link">
                        <h1>{{article.title}}</h1>
                        <p>{{article.description}}</p>
                        <span>Read more...</span>
                    </nuxt-link>
                </div>

                <!-- 分页 -->
                <nav>
                    <ul class="pagination">

                        <!-- ngRepeat: pageNumber in $ctrl.pageRange($ctrl.totalPages) -->
                        <li class="page-item" :class="{active: item===page}" v-for="item in totalPage" :key="item">

                            <nuxt-link class="page-link" :to="{
                                name: 'home',
                                query: {
                                    page: item,
                                    tag: $route.query.tag,
                                    tab: tab
                                }
                            }">{{item}}</nuxt-link>

                        </li><!-- end ngRepeat: pageNumber in $ctrl.pageRange($ctrl.totalPages) -->
                       
                    </ul>
                </nav>
            </div>

            <div class="col-md-3">
                <div class="sidebar">
                    <p>Popular Tags</p>

                    <div class="tag-list">
                        <nuxt-link :to="{
                            name: 'home',
                            query: {
                                tab: 'tag',
                                tag: item
                            }
                        }" class="tag-pill tag-default"
                         v-for="item in tags" :key="item">{{item}}</nuxt-link>
                    </div>
                </div>
            </div>

        </div>
    </div>

</div>
</template>

<script>
import { getArticles, getFeedArticles,
 addFavorite, deleteFavorite } from '@/api/article'
import { getTags } from '@/api/tag'
import { mapState } from 'vuex'
export default {
    name: 'home',
    async asyncData({ query, store }) {
        const page = Number.parseInt(query.page || 1)
        const limit = 20
        const { tag } = query
        const tab = query.tab || 'global_feed'
        const loadArticles = store.state.user && tab === 'your_feed'
         ? getFeedArticles : getArticles

        const [ articleRes, tagRes ] = await Promise.all([
            loadArticles({
                limit,
                offset: (page - 1) * limit,
                tag
            }),
            getTags()
        ])
        
        const { articles, articlesCount } = articleRes.data
        const { tags } = tagRes.data

        articles.forEach(article => article.favoritedDisabled = false)

        return {
            articles,
            articlesCount,
            tags,
            limit,
            page,
            tag,
            tab: query.tab || 'global_feed'
        }
    },
    watchQuery: ['page', 'tag', 'tab'],
    computed: {
        ...mapState([ 'user' ]),
        totalPage () {
            return Math.ceil(this.articlesCount / this.limit)
        }
    },
    methods: {
        async onFavorite(article) {
            article.favoritedDisabled = true
            console.log(article.favoritedDisabled)
            if(article.favorited){
                // 取消点赞
                await deleteFavorite(article.slug)
                article.favorited = false
                article.favoritesCount += -1
            }else{
                // 点赞
                await addFavorite(article.slug)
                article.favorited = true
                article.favoritesCount += 1
            }
            article.favoritedDisabled = false
        }
    }
}
</script>
